Question: How long did Lance Armstrong participate in the Tour de France?
Paraphrase: How many times did Lance Armstrong participated in Tour de France?
SPARQL (Wikidata):  select distinct ?obj where { wd:Q2172 wdt:P1344 ?obj . ?obj wdt:P31 wd:Q33881 } 
Answer: 2010 Tour de France, 2004 Tour de France